Rotary engine.



J. H. VAN DEVENTER.

ROTARY ENGINE.

APPLIGATION FILED MAY 15,1911.

1,026,887, Patented May 21, 1912.

A 2 SHEETS-SHEET 1.

J. H. VAN DEVENTER.

ROTARY ENGINE.

'APPLICATION FILED MAY 1s, 1911.

Patented May 21, 1912.

z SHEETS-SHEET 2.

INVENTOE ZM M UNITED sTATEs PATENT oEEIoE;

JOHN H. VAN DEVENTER, 0F BUFFAIiO, NEW YORK, ASSIGNOR T0 BUFFALO FORGECOMPANY, 0F BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

ROTARY ENGINE.

To all whom it may concern:

Be it known that l, JOHN HERBERT VAN DEvEN'rEn, a citizen ot the UnitedStates of America, residing `at Buffalo., in the county of Erie andState of New York, have invented certain new and useful Improvements inRotary Engines, of which the following` is a full, clear, and exactdescription.

`My invention relates to rotary engines and more particularly to engineswith rotors cach having a plurality of spirally disposed andintermeshing tooth blades.

Some of the objects of my invention have been to provide a rotary enginein which all end thrust on the shafts might be eliminated; also one inwhich there should be substantially no leakage of the fluid underpressure between ends of the rotors andthe engine heads. To this end Iemploy two or more rotors each provided with one or moreI right hand andone or more left hand spirally arranged tooth blades and l place theadmission ports between the intermeshing rotors and at the junctionpoints of the right. hand and left hand spil-ally arranged tooth blades;thus I accomplish the above objects and at the same time provide a verypowerful rotary engine, which occupies a small space.

Another object has been to provite a rotary engine which should be veryeiliv cient in operation andeconomical in fluid consumption. ln order toattain this object I have arranged the inlet porty of my engine so thatthe fluid under its initial pressure is cut oti` from each bucket'. asthe rotors revolve. b v the bucket which follows. or shortly after thetime of admission of the lhiid to said buckets. The fluid eontained ineach bucket after the supply has been cut ott, continues to expand untileach bucket has tinished its cycle or until it is opened to theatmosphere, into which it is then exhausted.

By slight nualitication of the principal torm shown and described inthis application, l provide a reversible aml also a multiple stagerotary engine which is very etlicient and compact.

The above. together with many other advantages which will bc apparent tothose skilled in the art. have been accomplished by my invention hereinIshown and dcscrilwd.

ln the specilication and appended claims the term fluid will be used asa general term for the pressure medium but the engine is Specificationof Letters Patent.

Application led May 15, 1911.

.of the same. sectional end vlew of the same and is taken Patented May'21, 1912.

Serial No. 627,166.

especially adapted for the use Aof steam and obviously it is applicableto be driven with either steam or compressed air as well as any fluidunder pressure.

Reference is to be had to the accompanying drawings, forming art of thespecification, in which like eiaracters of refer ence indicate like artsthroughout the several views of whie Figure 1 is a plan view of my enine. Fig. 2 is an end sectional elevation o the same taken on line A-Bof Fig. 1. Fig. 3 is a bottom View of the en ine with the rib brokenaway and shows t e buckets as formed by the tooth blades on the rotors.Fig. 4 is a sectional end elevation and shows an inlet port of amodified shape. Fig. 5 is a diagrammatical view of a slightly modiodform of my invention and shows a twin or two-stage eti'ect. Fig. 6 is adiagrammatical sectional end view of the modified Jform shown in Fig. 5and is taken on line (l-D of that figure. Fig. 7 is a diagramn'iatiealfront elevation of a reversible engine. Fig. 8 is a diagrammat-ical planview Fig t) is a diagrammatical on line lL-F of Fig. 8.

In the drawings, (Figs. 1 to 3) 10 is the base of my engine which isprovided with .suitable bearings 11. Shafts 12 and 1Q are rotatablycarried by the bearings 11 and the said shafts have mounted thereon, ina rigid manner, rotors 13 and 13 respectively. Each rotor is providedwith 'a plurality of right hand spit-ally disposed tooth blades 14extending across the rotor for substantiall one-halt its length and aplurality of le t hand spirally disposed tooth blades 15 extendingacross the rotor for substantially the remaining halt of its length. Thesaid right hand and left hand tooth blades meet aml join one another atthe center of each rotor. The right hand tooth blades 14 of termeshingtooth blades, has been developed.

Obviously if desired this rib may be continued around the rotors and`nibstantially surround them and thus form a casing in which the exhaustfluid may be confined and from which it may be carried to any desiredplace. 174 is the inlet port which is disposed at the center of thelength ot' the rib lo and near its peak. This port is preferablydisposed in a horizontal plane and extends -from one side of the ribthrough to the opposite side so that'the [luid entering under pressurewill be caused to impinge on both rotors at the saine time. Suitableports 1S and 1.9 are provided through which the tiuid is conducted tothe inlet port 17, the port lt) being provided at its outer end with ascrewthread, whereby suitable piping may be connected thereto. l

In Fig. t I have shown a modified inlet port 17a. In this figure theupper wall of the port is shown concave thereby producing a turbineetl'ect by causing the Huid to impinge upon the tooth blade at a tangentto the path of travel of said tooth blade.

In Figs. 5 to 9 I have shown in a diagrammatieal manner a few of themany vav ried modifications of my invention. .In Figs. 5 and 6, threerotors 20, 2,1 and 22 are i disposed one above the other with theirtooth blades intermeshing. These rotors are provided with shafts 23, 24and 25 respectively. Two ribs, 2o kand QT, are used and are placed onopposite sides of the engine; rib 26 being arranged between rotors 20and 2l, and rib Q7 between rotors 21 and 22. Thus a twin el'ect or atwo-stage elfect may be obtained by employing only three rotors insteadof four and thereby making avery compact engine. The direction otrotation of these rotors is indicated by the arrows in Fig. 6. Thenarranged as a twin engine the fluid under its initial pressure will besupplied to inlet ports of both ribs but when arranged as a two-stageengine the fluid under initial pressure may, for instance, be suppliedto the inlet. port. of the rib 26 and the inlet port of the rib suppliedwith the exhaust from the roto-rs 20 and 21. Obviously, when used as atwostage engine, as above described. the inlet ports carrying the fluidto the rotors l and 22 may be increased in length so as to coinpensatet'or the decreased pressure ot the tiuid which is exhausted from therotors 2t) and 2l. l `urther1nore by employing four rotors a tripleeti'ect may be produced.

In Figs. T to 9 a reversible engine is shown. ln this inoditication twoshafts 2S and 29 are employed and upon each is mounted a rotor 30 and 8lrespectively. 'Ihe blades of each ot these rotors are preferablydisposed in three alternately arranged positions. 'a'. c., the rotor 30has two sections 32 and 33 which are provided with lct't hand spirallydisposed tooth blades and one section 34 with right hand spirallydisposed tooth blades, and the rotor 3l has two sections provided withright hand spirally disposed tooth blades 35 and 3G and one section,provided with left hand spirally disposet tooth blades 3T. Thesesections in the rotors are so arranged that the tooth blades of onerotor mesh with those ot the other rotor. Two ribs 3S and it!) areprovided in this type. oi engine. The ribs are arranged one on each sideot thc rotors and preferably are each of such a length as to only extendacross the rotors` for about' twothirds o't' their length. ri`hc ribnvextends across thefctions 32 and B-t of rotor 30 and sections 85 and3T of rotor l while the rib Si) preferably extends across the sections33 and 3l of rotor 3() and Athe sections f'and 37 of rotor 3l. throughthe inlet port in the rib 23.*? rotors will revolve in the direction ot'the full line arrows. llt) and il, but when the. tluid enters the inletport in the r-.b 3S) the rotors will then revolve `in the direction ofthe dotted line arrows #l2 and 23. i

By referring to Fig. l it will clearly be seen that between the toothblade i-- on the rotor 13L and the two tooth biades 4.5 and 46 on therotor 153 betwtcn which the tooth blade 4.4 meshes, is formed a bucket4T. llach rotor being provitjled with a plurality of right hand andlet't hand spirally dis'- posed tooth blades. the formation ot' but onedouble-sided bucket is started by the internieshing' tooth blades at anyone time. .it substantially the instant when such a bucket is startedduring the revolution ot' the rotors, the tiuid under pressure is madeto iinpinge thereon, thus causing the capacity of said bucket togradually increase on account ot' the recession of the points ot` meshot' the tooth blades forming the saine toward the ends of the rotors.Then any sucl'nbucket is under pressure and the rotors are thcrebv therevolved. thc tooth bladesI forming one side ot said bucket when passingthe port cut o'tl the supply ot liuid from said bucket- (see Fig. 3).thus allowing the fluid contained in said bucket to expand until it hasdeveloped its 'full capacity or until the tooth blades it'orniing saidbucket. cease to mesh. It is evident that the ratio of expansion may bell'hen the tlnid is 'forced IO O atthe junction points of the right handandv left hand spiral tooth blades at the center of each rotor angularpockets are formed land as the fluid under pressure is admitted at thispoint, any leakage at the end of the rotors is impossible. The onlyplace where leakage may occur is between the perimeters of the rotorsand the rib butl as it is possible to make a very good and practicallynon-leaking contact at this point, there is very little leakage in myengine thus making it very efficient in o eration.

Obviously some detailed modifications of my invention as herein shownand described may be made without departing from the spirit of myinvention and I do not wish to be limited to the exact embodiment hereinshown and described.

Having thus described my invention, what I claim is:

. l. In a rotary engine, the combination of two or more intermeshing andengaging rotors. shafts secured in said rotors and 10- tatably mountedin suitable bearings, each rotor having a plurality of right handspirally disposed tooth blades extending from a plurality ofcircumferential points on said rotors located in a plane at r1ght anglesto the axis thereof toward one end of said rotors, and a pluralityofleft hand spirally disposed tooth blades extending from said pluralityof circumferential points toward the opposite end of said rotors, saidright and left hand'tooth blades of each rotor meeting and joiningr andthereby forming angular pockets and a fluid inlet provided with a portfor conducting fluid under pressure. to said rotors, said port heilig solocated and formed that said conducted fluid will be impinged within theangular' pockets formed by said tooth blades.

2. In a rotary engine, the combination of two or more intermeshing andengaging rotors, shafts secured in said rotors and ro-,

tatably mounted in suitable bearings, each rotor having a plurality ofright hand spirally disposed tooth blades extending from a plurality ofcircumferential points on said rotors located in a plane at right anglesto the axis thereof toward one end of said rotors. -and a plurality ofleft hand spirally disposed tooth blades extending from said pluralityof circumferential points toward the opposite end of said rotors, saidright hand and left hand spirally disposed tooth blades of one rotormeshing respectively with said left hand and right hand spirallydisposed tooth blades of another rotor. whereby buckets are formedbetween the meshing tootlfblades of said rotors, and a fluid inlet.provided with a port for conducting fluid under pressure to said rotors,said port being so located and formed that said conducted fluid will beimpinged within the. buckets formed by said tooth blades.

3. In a rotary engine the combination of two or more intel-meshing andengaging rotors, shafts secured in said rotors and rotatably mounted insuitable bearings each rotor having a plurality of right hand spirallydisposed tooth blades extending from a plurality of circumferentialpoints on said rotorsV located in a plane at rlght angles to the axisthereof toward one end of said rotors and a plurality of left handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the opposite end of said rotors, saidright and left hand tooth blades of each rotor meeting and joining andthereby forming angular pockets, and said right hand and left handspirally disposed tooth blades of one rotor meshing respectively withsaid left hand and right hand spirally disposed tooth blades of anotherrotor, whereby buckets are formed between the meshing tooth blades ofsaid rotors, and a fluid inlet provided with a port for conducting fluidunder pressure to said rotors, said port being so located and formedthat said conducted fluid will be impin Ved within the angular pocketsformed by said tooth blades.

4. In a rotary engine the combination of two or or more intermeshing andengaging rotors. shafts secured in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of right hand spirallydisposed tooth blades extending from a plurality of circumferentialpoints on -said rotors located in a plane at right angles to the axisthereof toward one end of said rotors, and a plurality of left handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the opposite end of said rotors, saidright and left hand tooth blades of each rotor meeting and joining andthereby forming angular pockets and a fluid inlet provided with a porthaving lateral passages leading into said pockets whereby the conductedfluid impacts in said pockets and against said tooth bladessubstantially in the direction of rotation of said rotors.

5. ln a rotary engine the combination of two or more inter-meshing andengaging rotors, shafts secured in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of right hand 'spirallydisposed tooth blades extending points toward the opposite end 'of saidrotors, said right and left hand tooth blades of each rotor meeting andjoining and thereby forming angular pockets, and a rib extendingsubstantially parallel to-the axes of said rotors and in contact withthe peripheries of said rotors for at least a portion of theircircumferences, said rib being provided with a port for conducting fluidunder pressure to the said angular pockets of said rotors.

G. In a rotary engine the combination of two or more mtermeshing andengaging rotors, shafts secured in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of right hand spirallydisposed toot-h blades extending from a plurality of circumferentialpoints on said rotors located in a plane at right angles to the axisthereof toward one end of said rotors and a plurality of left handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the opposite end of said rotors, saidright and left hand tooth blades of each rotor meeting and joining andthereby forming angular pockets, and a rib extending substantiallyparallel to the axes of said rotors and in contact with the peripheriesof said rotors for at least a portion of theirA circumferences, said ribbeing provided with lateral passages leading into said pockets wherebythe conducted fluid impacts in said pockets and against said toothblades substantially in the direction of rotation of said rotors. f e

7. In a rotary engine the combination of two or more inter-meshing andengaging rotors, shafts secured in said rotorsand rotatably mounted insuitable bearings, each rotor having a plurality of right hand spirallydisposed tooth blades extending from a plurality of circumferentialpoints on said rotors located in a plane at right angles to the axisthereoftoward one end of said rotors and a plurality of left handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the opposite end of said rotors, saidright hand and left hand spirally disposed tooth blades of one rotormeshing respectively with said left hand and right hand spit-allydisposed tooth blades of another rotor, wherebv buckets are formedbetween `the meshing tooth blades of said rotors, and

a rib extending substantiallyv parallel to the axes of said rotors andin contact with the peripheries of said rotors for at least. a portionof their circumferences, said rib being provided with a port forconducting fluid under pressure to said buckets of said rotors.

S. ln a rotary engine tl'ielcombination of two or more intermeshing andengaging rotors, shafts mounted in said rotors and rotatably mounted insuitable bearings, each l.

rotor having a plurality of right hand spirally disposed tooth bladesextending from a plurality of circumferential points on said rotorslocated in a plane at right angles to the laxis thereof toward one end osaid rotors and a plurality of left hand spiralljT disposed tooth bladesextending from said plurality of. circumferential points toward' toothblades substantially in the direction of rotation of said rotors. l

9. ln a rotary engine the combination of two or more intermeshing andengaging rotors, shafts secured in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of right hand spirallydisposed tooth blades extending from a plurality of circumferentialpoints on said rotors located in a plane at right angles to the axisthereof toward one end of said rotors and a plurality of left handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the opposite end of said rotors, saidright and left hand tooth blades of each rotor meeting and joining andthereby forming angular pockets, a rib extending substantiall y parallelto the axes of said rotors and in contact with the peripheries ofsaidrotors l y for at least a portion of theirfcircumferences, and one ormore inlet ports located in said rib and opening into said. intermeshingtooth blades substantially at the-,junction of said right and left handspirally disposed tooth blades. l

10. ln a rotary engine the combination of two or more intermeshing andengaging rotorsv` shafts mounted in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of right hand spirallydisposed toot-h blades extending from a plurality of circumferentialpoints on said rotors located in a plane. at right angles to the axisthereof toward one end of said rotors and a plurality of lett handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the. opposite end of said rotors, saidrightl disposed tooth blades of another rotor, whereby buckets areformed between the meshing tooth blades of said rotors, a rib extendingsubstantially pa 'allel to the axes of said rotors and in contact withthe peripheries of said rotors for at least a portion ot` theircireumferences, and one or more inlet ports located in said rib andopening into said .buckets at substantially tbe junction of said rightand left hand spirally disposed tooth blades.

ll. In a rotary engine the combination of two or more intermeshing andengaging rotors, shafts secured in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of right hand spi rallydisposed tooth blades extending from a plurality of circumferentialpoints on said rotors located in a plane at right angles to the axisthereof toward one end of said rotors and a plurality of left handspirally disposed tooth blades extendingt'rom said plurality ofcircumferential points toward the opposite end of said rotors, saidright and left hand tooth blades of each rotor meeting and joining andthereby forming angular pockets, a rib extending substantially parallelto the axes of said rotors and iu contact with the peripheries of saidrotors t'or at least a portion of their circumferelues, and one or moreinlet ports located in said rib and opening into said intermeshing toothblades at substantially the junction ot' said right and left handspirally disposed tooth blades, said ports being so arranged that theadmission of the fluid under pres` sure into any pair of intermeshingtooth blades is cut ott by the succeeding intermesliing tooth bladesbefore the said first mentioned tooth blades have developed their fullcapacity.

12. In a rotary engine the combination ot' two or more intermeshing andengaging rotors, shafts secured in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality ot' right hand spirallydisposed` tooth blades extending from a plurality oit' circumferentialpoints on said rotors located in a plane at right angles to the axisthereof toward one end of said rotors and a plurality of lett handspirally disposed tooth blades extending from said plurality otcircumferential points to the opposite end of said rotors, said rightand left hand tooth blades ot each rotor meeting and joining and therebyforming angular pockets, a rib extending substantially parallel to theaxes of said rotors and in contact with the peripheries ot' said rotorsfor at least a portion of their circumferences, and one or more inletports located in said rib and openi'ng into said intermeshing toothblades `at substantially the junction of said right and left handspirally disposed tooth blades, said ports being so arranged 1n said ribthat a curve drawn parallel to said right or left hand tooth blades andtangent to the curve in which that port orifice which is the greatestdistance from the formation of said pockets eut said rib, shall beshorter than the full length ot either said right or said left handtooth blades of each of said rotors, whereby the admission of the fluidunder pressure into any pair of intermeshing tooth blades is cut. ott'by the succeeding intermeshing tooth blades before the said tirstmentioned tooth blades have developed their tull capacity.

13. In a rotary engine the combination of two or more interlneshing andengaging rotors, 'shafts mounted in said rotors and rotatably mounted insuitable bearings, each rotor having a plurality of' right hand spirallydisposed tooth blades extending from `a plurality of `circumferential`points on said rotors located in a plane at right angles to the axisthereof toward one end of said rotors and a plurality of left handspirally disposed tooth blades extending from said plurality ofcircumferential points toward the opposite end of said rotors, saidright hand and left hand spirally disposed tooth blades of one rotormeshing respectively with said lett hand and right hand spirallydisposed tooth blades of another rotor, whereby buckets are formedbetween the meshing tooth blades of said rotors, a rib extendingrsubstantially parallel to the axis of said rotors and in contact withthe peripheries of said rotors for at least a portion of theircircumferences. and one or more inlet ports located in said rib andopening into said buckets vat substantially the junction of said rightand left hand spirally disposed tooth blades, said ports being soarranged that the admission of the fluid under pressure into any bucketis cut off by the tooth blades forming one side of the succeeding bucketbet'ore the said first mentioned bucket has developed its full capacity.

14. In a reversible rotary engine the combination of two or moreinter-meshing and engaging rotors, shafts secured in said rotors and.rotatahlymounted in suitable bearings, each rotor having three or moresections, each alternate section on each rotor being provided with aplurality of right hand spirally disposed tooth blades and the otheralternate section of the same rotor being provided with a plurality ofleft hand spirally disposed tooth blades, the said right and left handtooth blades on each rotor meeting and joining so as to term angularpockets.

15. In a reversible rotary engine the combination of two or moreintermeshing and engaging rotors, shafts secured in said rotors androtatably mounted in suitable bearings, each rotor having three or moresecl tions, each alternate section on each rotor l engagingy rotors,shafts secured in said rotors and rotatably mounted in suitablebearings, each rotor having three or more sections, each alternatesection on each rotor being provided with a plurality of right handspirally disposed tooth blades and the other alternate section of thesame rotor being provided with a plurality of left hand spirallydisposed tooth blades, the said right and left hand tooth blades on eachrotor meeting and joiningso as to form angular pockets, the right handand left hand tooth blades on one rotor meshing respectively with theleft hand and right hand tooth blades of another rotor, whereby bucketsare formed between the meshing tooth blades of the said rotors.

17. In a reversible rotary engine the combination of two,y or moreintermeshing and engaging rotors, shafts secured in said roi tors androtatably mounted in suitable bearings, each rotor having three or moresections, each alternate section on each rotor being provided with aplurality of righty hand spirally disposed tooth blades and the otheralternate section yof the same rotor being provided with a plurality ofleft hand spirally disposed tooth blades, the said right and left handtooth blades on each rotorK meeting and joining so as to form angularpockets, a rib extending across said angular pockets on one side of saidrotors and a rib extending across said angular pockets on the oppositesideof said rotors, each of said ribs being substantially parallel tothe axes of said rotors and in contact with the peripheries of saidrotors for at least a portion of their circumferences.

18. In a reversible rotary engine the combination of two or moreintermeshing and engaging rotors, shafts secured in, said rotors androtatably mounted in suitable bearings, each rotor having three or moresections, each alternate section on each rotor beingA provided with aplurality of right hand spirally disposed tooth blades and the otheralternate section of the same rotor being provided with a plurality ofleft hand spirally disposed tooth blades, the rightand left hand toothblades on one rotor meshing respectively with the left hand and righthand tooth blades of another rotor, whereby buckets are formed betweenthe meshing tooth blades of the said rotors, a rib extendrotors and arib extending across said buckets on the opposite side of said rotors,each of said ribs being substantially parallel to the laxes of saidrotors and in contact with thev peripheries of' said rotors for at leasta portion of their circumferences.

19. In a reversible rotary engine the combination of two or moreintermeshing and engaging rotors, shafts secured in said rotors androtatably mounted in suitable bears ings, each rotor having three ormore sections, each alternate section on each rotor being provided witha plurality of right hand spirally disposed tooth blades and the otheralternate section of the same rotor being provided with a plurality ofleft hand spirally disposed tooth'blades, the said right and left handtooth blades on each rotor meeting and joining so as to form angularpockets, a rib extending across said angular pockets on one side of saidrotors and a rib extending across said angular pockets on the oppositeside of said rotors, each of said ribs being substantially parallel tothe aXes of said rotors and in contact with the peripheries of saidrotors for at least a portion of their circumferences, and one or moreinlet ports located in each of said ribs and openings into theintermeshing tooth blades at substantially the junction of each righthand and left hand set of tooth blades where the said angular pocketsare formed.

20. .In a reversible rotary engine the combination of two or moreintermeshing and engaging rotors, shafts secured in sald rotors androtatably mounted in suitable bear ings, each rotor having threeor moresections, each alternate section on ea'ch rotor being provided with aplurality of right. Ahand spirally disposed tooth blades and theother.alternate section of the same rotor being provided with aplurality of left hand' spirally disposed tooth blades, the right andleft hand tooth blades on one rotor meshing respectively with the lefthand and right hand tooth blades of another rotor, whereby buckets areformed between the meshing tooth blades of the said rotors, a ribextending across said buckets on one side of said rotors, a ribextending across said buckets on the opposite side of said rot-ors, eachof said ribs being substantially parallel to the' being provided with aplurality of right hand spirally disposed tooth blades and the otheralternate section of the same rotor being provided with a plurality ofleft hand splrally disposed tooth blades, the said right and left handtooth blades on each rotor meeting and joinin so as to form angularpockets, a rib exten ing across said angular pockets on one side of saidrotors and a rib extendin across said angular pockets on the oppositeside of said rotors, each of said ribs being substantially parallel tothe axes of said rotors and in cont-act with the peripheries of saidrotors for at least a portion of their circumferences, and one or moreinlet ports located in each of said ribs and openings int'o theinterineshing tooth blades at substantially the junction of each righthand and left hand set of tooth blades where the said angular pocketsare formed, said ports being so arranged that the admission of the tluidunder pressure into any pair of intermeshing tooth blades is cut off bythe succeeding informes-hing tooth blades before the said irst mentionedtooth blades have developed their full capacity.

22. In a reversible rotary engine the combinationA of two or moreintermeshing and engaging rotors, shafts secured in said rotors androtatably mounted in suitable bearings, each rotor having three or moresections, each alternate section on each rotor being provided with apluralit of right hand spirally disposed tooth bla es and the otheralternate section of the same rotor being provided with a plurality ofleft hand spirally disposed tooth blades, the right and left hand toothblades on one rotor meshing respectively with the left hand and righthand tooth blades of another rotor, whereby buckets are formed betweent-he meshing tooth blades of the said rotors, a rib extending acrosssaid buckets on one side of said rotors, a rib extendin(lr across saidbuckets on the opposite side o? said rotors, each of said ribs beingsubstantially parallel to the axes of said rotors and in contact withthe peripheries of said rotors for yat least a portion of theireircumferences, and one or more inlet ports located in each of said ribsand opening into said buckets, said ports being so arranged that theadmission of the fluid under pressure into any bucket is cut ott by thetooth blades forming one Side of the succeeding bucket before the saidfirst mentioned bucket has developed its full capacity. y

In witness whereof, I have hereunto set my hand in the presence of twowitnesses.

JOHN H. VAN DEVENTER.

Witnesses:

JOHN M. CIIIPMAN, J. WM. ELLIS.

